Post-etch treatment system for removing residue on a substrate

ABSTRACT

A post-etch treatment system is described for removing photoresist and etch residue formed during an etching process. For example, the etch residue can include halogen containing material. The post-etch treatment system comprises a vacuum chamber, a radical generation system coupled to the vacuum chamber, a radical gas distribution system coupled to the radical generation system and configured to distribute reactive radicals above a substrate, and a high temperature pedestal coupled to the vacuum chamber and configured to support the substrate. The high temperature pedestal comprises a scored upper surface configured to minimize substrate slippage.

CROSS REFERENCE TO RELATED APPLICATIONS

The present invention is related to co-pending U.S. patent applicationSer. No. 11/390,192, entitled “METHOD OF REMOVING RESIDUE ON ASUBSTRATE,” filed on even date herewith, and co-pending U.S. patentapplication Ser. No. 11/390,196, entitled “GAS DISTRIBUTION SYSTEM FOR APOST-ETCH TREATMENT SYSTEM,” filed on even date herewith, the entirecontents of which are herein incorporated by reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a method and apparatus for treating asubstrate, and more particularly to a post-etch treatment system forreduced damage treatment of a substrate following an etching process.

2. Description of Related Art

During semiconductor processing, a (dry) plasma etch process can beutilized to remove or etch material along fine lines or within vias orcontacts patterned on a silicon substrate. The plasma etch processgenerally involves positioning a semiconductor substrate with anoverlying patterned, protective mask layer, for example a photoresistlayer, in a processing chamber. Once the substrate is positioned withinthe chamber, an ionizable, dissociative gas mixture is introduced withinthe chamber at a pre-specified flow rate, while a vacuum pump isthrottled to achieve an ambient process pressure. Thereafter, a plasmais formed when a fraction of the gas species present are ionized byelectrons heated via the transfer of radio frequency (RF) power eitherinductively or capacitively, or via microwave power using, for example,electron cyclotron resonance (ECR). Moreover, the heated electrons serveto dissociate some species of the ambient gas species and createreactant specie(s) suitable for the exposed surface etch chemistry. Oncethe plasma is formed, selected surfaces of the substrate are etched bythe plasma. The process is adjusted to achieve appropriate conditions,including an appropriate concentration of desirable reactant and ionpopulations to etch various features (e.g., trenches, vias, contacts,etc.) in the selected regions of the substrate. Such substrate materialswhere etching is required include silicon dioxide (SiO₂), low dielectricconstant (i.e., low-k) dielectric materials, poly-silicon, and siliconnitride. Once the pattern is transferred from the patterned mask layerto the underlying layer, using, for example, dry plasma etching, theremaining layer of photoresist, and post-etch residues, are removed viaan ashing (or stripping) process. For instance, in conventional ashingprocesses, the substrate having the remaining photoresist layer isexposed to an oxygen plasma formed from the introduction of diatomicoxygen (O₂) and ionization/dissociation thereof. However, formation ofplasma in close proximity with the substrate can lead to uncontrolledexposure to high energy charged particles (e.g., energetic electrons,etc.) and electro-magnetic (EM) radiation (e.g., ultraviolet (UV)radiation), which may cause damage to underlying layers and/orstructures that is unacceptable to the device manufacturers.

SUMMARY OF THE INVENTION

The present invention relates to a system for treating a substrate, andto a system for treating a substrate with atomic or molecular radicals.

According to one embodiment, a treatment system is described forremoving residue on a substrate using a flow of atomic or molecularradicals. According to another embodiment, a treatment system includes aprocess chamber, including a process space; a remote radical generationsystem coupled to the process chamber and configured to receive processgas and produce radicals from the process gas and transport the radicalsto the process space in the process chamber above the substrate; apedestal coupled to the process chamber and configured to support asubstrate in the process space of the process chamber and control thetemperature of the substrate. The pedestal includes one or more groovesformed in an upper surface of the pedestal, and wherein at least one ofthe one or more grooves extends to an edge of the pedestal. Alsoincluded in the system is a vacuum pumping system coupled to the processchamber and configured to evacuate the process chamber. According toanother aspect of the invention a treatment system includes a processchamber, including a process space, and a remote radical generationsystem coupled to said process chamber and configured to receive processgas and produce radicals from said process gas and transport saidradicals to said process chamber above the substrate. Means forsupporting the substrate with minimal slippage of the substrate ispositioned in said process chamber. Also included is means for heatingthe substrate, and a vacuum pumping system coupled to said processchamber and configured to evacuate said process chamber.

BRIEF DESCRIPTION OF THE DRAWINGS

In the accompanying drawings:

FIGS. 1A, 1B, and 1C show a schematic representation of a procedure forpattern etching a thin film;

FIG. 2 shows a schematic diagram of a treatment system according to anembodiment of the present invention;

FIG. 3 shows a schematic diagram of a treatment system according toanother embodiment of the present invention;

FIG. 4 shows a schematic diagram of a treatment system according toanother embodiment of the present invention;

FIG. 5 shows a schematic diagram of a treatment system according toanother embodiment of the present invention;

FIGS. 6A and 6B show a schematic diagram of a treatment system accordingto another embodiment of the present invention;

FIG. 7 shows a schematic diagram of a treatment system according toanother embodiment of the present invention;

FIGS. 8A and 8B shows a schematic diagram of a treatment systemaccording to another embodiment of the present invention;

FIG. 9 presents a top view of an upper surface of a substrate holderaccording to an embodiment of the present invention;

FIG. 10 presents a top view of an upper surface of a substrate holderaccording to another embodiment of the present invention;

FIG. 11 presents a top view of an upper surface of a substrate holderaccording to another embodiment of the present invention; and

FIG. 12 presents a method of removing residue on a substrate accordingto an embodiment of the present invention.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

In the following description, in order to facilitate a thoroughunderstanding of the invention and for purposes of explanation and notlimitation, specific details are set forth, such as a particulargeometry of the treatment system and descriptions of various processes.However, it should be understood that the invention may be practiced inother embodiments that depart from these specific details.

In material processing methodologies, pattern etching comprises theapplication of a thin layer of light-sensitive material, such asphotoresist, to an upper surface of a substrate, which is subsequentlypatterned in order to provide a mask for transferring this pattern tothe underlying thin film on a substrate during etching. The patterningof the light-sensitive material generally involves exposure by aradiation source through a reticle (and associated optics) of thelight-sensitive material using, for example, a micro-lithography system,followed by the removal of the irradiated regions of the light-sensitivematerial (as in the case of positive photoresist), or non-irradiatedregions (as in the case of negative resist) using a developing solvent.

For example, as shown in FIGS. 1A through 1C, a mask comprisinglight-sensitive layer 3 with pattern 2 (such as patterned photoresist)can be utilized for transferring feature patterns into a thin film 4 ona substrate 5. The pattern 2 is transferred to the thin film 4 using,for instance, dry plasma etching, in order to form feature 6, and uponcompletion of etching, the mask 3 is removed. Conventionally, the mask3, as well as other residue such as halogen residue from polysiliconetching, are removed by immersing the substrate in plasma, such as anoxygen plasma, and the remaining mask and post-etch residue are ashed(or stripped). However, when dry cleaning substrates having sensitive ordelicate structures or layers, such as during front-end-of-line (FEOL)applications in semiconductor manufacturing, direct exposure to plasmacan have detrimental effects due to the presence of energetic (charged)particles, electro-magnetic (EM) radiation, etc.

According to one embodiment, a treatment system 100 is depicted in FIG.2 comprising a process chamber 110 having a pedestal 120 configured tosupport a substrate 125, upon which a treatment process, such as apost-etch treatment process, is performed. Substrate 125 can be, forexample, a semiconductor substrate, a wafer or a liquid crystal display.Additionally, a radical generation system 115 is coupled to the processchamber 110 via a radical delivery system 140.

The process chamber 110 is further coupled to a vacuum pumping system170 through a duct and a pressure control system (e.g., vacuum valve,etc.), wherein the pumping system 170 is configured to evacuate theprocess chamber 110, the radical delivery system 140, and the radicalgeneration system 115 to a pressure suitable for performing thetreatment process on substrate 125, and suitable for production ofradicals in the radical generation system 115.

Referring still to FIG. 2, the radical generation system 115 isconfigured to remotely generate atomic radicals or molecular radicals orboth from a process gas supplied from a gas supply system 160 throughone or more gas supply conduits 162. The radicals formed remotely inradical generation system 115 are transported through radical deliverysystem 140 and introduced to process space 145 above substrate 125. Theradical delivery system 140 introduces the radicals to process space 145while providing minimal impedance to the flow of radicals and inhibitingthe recombination of radicals prior to reaching the substrate surface.For example, the radical delivery system may include a duct having aduct inlet coupled to an outlet of the radical generation system 115,and a duct outlet coupled to the process chamber 110.

The radical generation system 115 is configured to produce one or morechemical radicals configured to chemically react with and remove anyremaining mask layer or residual photoresist, post-etch residue, etc.with minimal damage to substrate 125. For example, the radicalgeneration system 115 can include an upstream plasma source configuredto generate oxygen or fluorine radical from a process gas comprising anoxygen containing gas, or a fluorine containing gas, or both. Forinstance, the process gas can include oxygen (O₂), CO, CO₂, NO, NO₂, N₂O(or, more generally, N_(x)O_(y)), N₂, nitrogen trifluoride (NF₃), NH₃,O₃, XeF₂, ClF₃, or C₃F₈ (or, more generally, C_(x)F_(y)), or anycombination of two or more thereof, respectively. The radical generationsystem 115 can include an Astron® reactive gas generator, commerciallyavailable from MKS Instruments, Inc., ASTeX® Products (90 IndustrialWay, Wilmington, Mass. 01887).

In addition to supplying process gas to radical generation system 115,gas supply system 160 can be further configured to supply an auxiliaryprocess gas to radical generation system 115 through the one or more gassupply conduits 162. The auxiliary process gas can be utilized as acarrier gas to assist the transport of radicals formed in the radicalgeneration system 115 to process space 145, or the auxiliary process gascan be utilized to dilute the process gas and radicals formed from theprocess gas. The auxiliary gas may include an inert gas, such as a noblegas (i.e., He, Ne, Ar, Kr, Xe), or nitrogen (N₂), or a combinationthereof. For example, the addition of nitrogen to the radical generationsystem 115 with oxygen (O₂) can assist the dissociation of O₂.Furthermore, the gas supply system 160 can be configured to introducethe auxiliary process gas directly to process chamber 110 through one ormore auxiliary gas supply conduits 164.

Although not shown, the gas supply system 160 can comprise one or moregas sources, one or more control valves, one or more filters, and/or oneor more mass flow controllers. For instance, the flow rate of processgas or auxiliary process gas can range from approximately 1 sccm(standard cubic centimeters per minute) to approximately 10000 sccm (or10 standard liters per minute, slm). For example, the flow rate ofprocess gas or auxiliary process gas can range from about 1 slm to about5 slm. By way of further example, the flow rate of process gas orauxiliary process gas can range from about 3 slm to about 5 slm.

Downstream from the radical generation system 115, radicals flow throughthe radical delivery system 140 and into process space 145 withinprocess chamber 110. The radical delivery system 140 can be coupled to avapor line temperature control system (not shown) in order to controlthe temperature. For example, the temperature can be set to a valueranging from approximately 20 degrees C. to approximately 100 degreesC., and by way of another example, the temperature can be set to a valueranging from about 40 degrees C. to about 80 degrees C. Additionally,for example, the radical delivery system 140 can be characterized by ahigh conductance in excess of about 50 liters/second.

Once radical flow enters the process space 145, the radicals chemicallyreact with residues on the surfaces of substrate 125. The pedestal 120is configured to elevate the temperature of substrate 125 by virtue of aheating element 135 embedded within pedestal 120 being coupled to atemperature control system 130. Heating element 135 may be a resistiveheating element, or heating element 135 may comprise an array ofthermoelectric devices. Additional details for the use of thermoelectricdevices in a substrate holder are provided in pending U.S. patentapplication Ser. No. 10/809,787, entitled “METHOD AND APPARATUS FORRAPID TEMPERATURE CHANGE AND CONTROL” and filed on, the entire contentsof which are herein incorporated by reference. For example, thetemperature control system 130 can be configured to elevate thetemperature of substrate 125 up to approximately 500° C. In oneembodiment, the substrate temperature can range from about 40° C. toabout 500° C. In another embodiment, the substrate temperature can rangefrom about 100° C. to about 300° C. Additionally, process chamber 110can be coupled to temperature control system 130 configured to controlthe temperature of the chamber walls.

In addition to elevating the temperature of substrate 125, pedestal 120is configured to support substrate 125 during treatment. The pedestal120 can further comprise a lift pin assembly (not shown) capable ofraising and lowering three or more lift pins in order to verticallytransfer substrate 125 to and from an upper surface of the pedestal 120and a transfer plane in the process chamber 110.

In the lift pin assembly, the substrate lift pins can be coupled to acommon lift pin element, and can be lowered to below the upper surfaceof pedestal 120. A drive mechanism (not shown) utilizing, for example,an electric drive system (having an electric stepper motor and threadedrod) or a pneumatic drive system (having an air cylinder), providesmeans for raising and lowering the common lift pin element. Substrate125 can be transferred into and out of process chamber 110 through agate valve (not shown) and chamber feed-through passage, aligned on thetransfer plane, via a robotic transfer system (not shown), and receivedby the substrate lift pins. Once the substrate 125 is received from thetransfer system, it can be lowered to the upper surface of the pedestal120 by lowering the substrate lift pins.

The present inventors have recognized that conventional treatmentsystems such as post-etch cleaning systems include substrate clampingmechanisms (e.g. electrostatic chuck) to hold the substrate, and/orsubstrate back-side gas flow systems to facilitate temperature controlof the substrate. While such features may be used with some embodimentsof the invention, the present inventors determined that substrateclamping and/or wafer back-side gas flow is not necessary for post-etchcleaning processes, particularly where a remote radical generator isused. That is, the present inventors discovered that the pedestal of apost-etch cleaning system can be simplified to substantially reducecost. Thus, according to one embodiment of the present invention, thetreatment system includes a pedestal that does not have a clampingmechanism, does not have a back side gas flow mechanism, or does nothave either of these features.

In order to prevent the substrate from moving or slipping on pedestal120, the upper surface of pedestal 120 can be scored with one or moregrooves, wherein at least one of the one or more grooves extends to anedge of the pedestal. During the translation of substrate 125 to theupper surface of pedestal 120, the one or more grooves in the uppersurface of pedestal 120 minimize, for example, the formation of alubrication layer that may enable movement (or slippage) of substrate125. At least one of the one or more grooves extends to the edge ofpedestal 120 in order to permit the escape of ambient gases trappedbetween the backside of substrate 125 and the upper surface of pedestal120, which may cause the formation of the lubrication layer.

Furthermore, during the translation of substrate 125 from the uppersurface of pedestal 120, the one or more grooves in the upper surface ofpedestal 120 minimize, for example, the sticking (due to suction) ofsubstrate 125 to pedestal 120 when initially displacing the substrate125 from the upper surface of pedestal 120. At least one of the one ormore grooves extends to the edge of pedestal 120 in order to permit thepenetration of ambient gases between the backside of substrate 125 andthe upper surface of pedestal 120 to ease the substrate lift-off.

Referring now to FIGS. 9 through 11, several examples are provided forscoring the upper surface of a pedestal with one or more grooves. Thepedestal configuration shown in any one of FIGS. 9-11 can be used in anyof the processing systems disclosed herein. FIG. 9 depicts pedestal 120having a first array of grooves 701 and a second array of grooves 702that form a substantially rectangular pattern. The first array ofgrooves 701 and the second array of grooves 702 are substantiallyperpendicular to one another and extend to the peripheral edge ofpedestal 120. FIG. 10 depicts pedestal 120′ having a first array ofsubstantially radial grooves 801 and a second array of substantiallycircular grooves 802 that form a substantially circular pattern. Thefirst array of grooves 801 and the second array of grooves 802 aresubstantially perpendicular to one another, and the first array ofradial grooves 801 extend to the peripheral edge of pedestal 120′. FIG.11 depicts pedestal 120″ having an array of substantially radial grooves901 that extend to the peripheral edge of pedestal 120″.

As illustrated in FIG. 2, an exhaust line connects process chamber 110to vacuum pumping system 170. Vacuum pumping system 170 comprises avacuum pump to evacuate process chamber 110 to the desired degree ofvacuum, and to remove gaseous species from the process chamber 110during processing. An automatic pressure controller (APC) and anoptional trap can be used in series with the vacuum pump. The vacuumpump can include a dry roughing pump. Alternatively, the vacuum pump caninclude a turbo-molecular pump (TMP) capable of a pumping speed up to5000 liters per second (and greater). During processing, the processgas, or auxiliary process gas, or any combination thereof, can beintroduced into the process chamber 110, and the chamber pressure can beadjusted by the APC. For example, the chamber pressure can range fromapproximately 1 mTorr to approximately 50 Torr, and in a furtherexample, the chamber pressure can range from about 1 Torr to about 10Torr. The APC can comprise a butterfly-type valve, or a gate valve. Thetrap can collect by-products from the process chamber 110.

Additionally, any element within treatment system 100 can be coated witha ceramic material, such as aluminum oxide or yttrium oxide. Forexample, any element may be coated with a material selected from thegroup consisting of Al₂O₃, Sc₂O₃, Sc₂F₃, YF₃, La₂O₃, Y₂O₃, and DyO₃.

Still referring the FIG. 2, the treatment system 100 can further includea control system 180 configured to operate, and control the operation ofthe treatment system 100. The control system 180 is coupled to theprocess chamber 110, the pedestal 120, the temperature control system130, the radical generation system 115, the gas supply system 160, andthe vacuum pumping system 170.

The control system 180 can include a microprocessor, a memory, and adigital I/O port capable of generating control voltages sufficient tocommunicate and activate inputs of the treatment system 100 as well asmonitor outputs from the treatment system 100. Moreover, the controlsystem 180 is coupled to and exchanges information with process chamber110, the pedestal 120, the temperature control system 130, the radicalgeneration system 115, the gas supply system 160, and the vacuum pumpingsystem 170. A program stored in the memory is utilized to control theaforementioned components of treatment system 100 according to a storedprocess recipe. One example of processing system control system 180 is aDELL PRECISION WORKSTATION 610™, available from Dell Corporation,Dallas, Tex. The control system 180 may also be implemented as ageneral-purpose computer, digital signal process, etc.

However, the control system 180 may be implemented as a general purposecomputer system that performs a portion or all of the microprocessorbased processing steps of the invention in response to a processorexecuting one or more sequences of one or more instructions contained ina memory. Such instructions may be read into the controller memory fromanother computer readable medium, such as a hard disk or a removablemedia drive. One or more processors in a multi-processing arrangementmay also be employed as the controller microprocessor to execute thesequences of instructions contained in main memory. In alternativeembodiments, hard-wired circuitry may be used in place of or incombination with software instructions. Thus, embodiments are notlimited to any specific combination of hardware circuitry and software.

The control system 180 includes at least one computer readable medium ormemory, such as the controller memory, for holding instructionsprogrammed according to the teachings of the invention and forcontaining data structures, tables, records, or other data that may benecessary to implement the present invention. Examples of computerreadable media are compact discs, hard disks, floppy disks, tape,magneto-optical disks, PROMs (EPROM, EEPROM, flash EPROM), DRAM, SRAM,SDRAM, or any other magnetic medium, compact discs (e.g., CD-ROM), orany other optical medium, punch cards, paper tape, or other physicalmedium with patterns of holes, a carrier wave (described below), or anyother medium from which a computer can read.

Stored on any one or on a combination of computer readable media, thepresent invention includes software for controlling the control system180, for driving a device or devices for implementing the invention,and/or for enabling the controller to interact with a human user. Suchsoftware may include, but is not limited to, device drivers, operatingsystems, development tools, and applications software. Such computerreadable media further includes the computer program product of thepresent invention for performing all or a portion (if processing isdistributed) of the processing performed in implementing the invention.

The computer code devices of the present invention may be anyinterpretable or executable code mechanism, including but not limited toscripts, interpretable programs, dynamic link libraries (DLLs), Javaclasses, and complete executable programs. Moreover, parts of theprocessing of the present invention may be distributed for betterperformance, reliability, and/or cost.

The term “computer readable medium” as used herein refers to any mediumthat participates in providing instructions to the processor of thecontrol system 180 for execution. A computer readable medium may takemany forms, including but not limited to, non-volatile media, volatilemedia, and transmission media. Non-volatile media includes, for example,optical, magnetic disks, and magneto-optical disks, such as the harddisk or the removable media drive. Volatile media includes dynamicmemory, such as the main memory. Moreover, various forms of computerreadable media may be involved in carrying out one or more sequences ofone or more instructions to a processor of controller for execution. Forexample, the instructions may initially be carried on a magnetic disk ofa remote computer. The remote computer can load the instructions forimplementing all or a portion of the present invention remotely into adynamic memory and send the instructions over a network to thecontroller 180.

Control system 180 may be locally located relative to the treatmentsystem 100, or it may be remotely located relative to the treatmentsystem 100 via an internet or intranet. Thus, control system 180 canexchange data with the treatment system 100 using at least one of adirect connection, an intranet, or the internet. Control system 180 maybe coupled to an intranet at a customer site (i.e., a device maker,etc.), or coupled to an intranet at a vendor site (i.e., an equipmentmanufacturer). Furthermore, another computer (i.e., controller, server,etc.) can access control system 180 to exchange data via at least one ofa direct connection, an intranet, or the internet.

As noted above, the treatment system 100 of FIG. 2 provides remotegeneration of radicals and delivery of such radicals to the substratewithin the process chamber. Such a configuration can allow treatmentsuch as post-etch cleaning of the substrate while minimizing damage tothe substrate that can be caused by high energy charged particles inclose proximity to the substrate. However, use of the remote radicalgenerator can reduce the treatment rate of the substrate and/or causenon-uniform treatment of the substrate. The present inventors havediscovered that design features such as geometry of the radical deliverysystem can affect the uniform distribution of radicals, as well as therecombination of rate of radicals which affects treatment rate at thesubstrate. Generally, unimpeded flow of the radicals to the substratesurface reduces recombination to improve treatment rate, but providespoor uniformity of treatment. Conversely, providing impediments to thegas flow (such as a distribution plate) can improve uniformity, butreduce treatment rate. Thus, embodiments of the present inventioninclude different radical delivery systems that control uniformsubstrate treatment, and/or substrate treatment rate.

Referring now to FIG. 3, a treatment system 200 is depicted according toanother embodiment. The treatment system 200 can, for example, besimilar to the embodiment of FIG. 2, wherein like reference numeralsdesignate same or similar components. Treatment system 200 comprises aradical delivery system 240 having a gas distribution plenum 244 coupledto an outlet of the radical generation system 115 through duct 242. Thegas distribution plenum distributes radicals received from duct 242within a process space 245 through a plurality of openings formed in agas distribution plate 246. The gas distribution plenum 244 comprises asubstantially cylindrical volume.

The gas distribution plate 246 can be designed with a plurality ofopenings ranging in number from approximately 1 opening to approximately1000 openings, and desirably ranging in number from approximately 10openings to approximately 100 openings. Additionally, for example, thegas distribution plate 246 can be designed with a plurality of openings,each opening having a diameter ranging from approximately 1 mm toapproximately 100 mm, and desirably ranging from approximately 4 mm toapproximately 10 mm. Furthermore, for example, the gas distributionplate 246 can be designed with a plurality of openings, each openinghaving a length ranging from approximately 1 mm to approximately 100 mm,and desirably ranging from approximately 2 mm to approximately 20 mm.

In one embodiment, the one or more openings are distributed uniformly onthe gas distribution plate 246. Alternatively, in another embodiment,the distribution of the one or more openings is not uniform. Forexample, there may be more openings within a peripheral region of gasdistribution plate 246 than within a central region of gas distributionplate 246.

The gas distribution plate 246 may be fabricated from a metal, such asaluminum or anodized aluminum, or a ceramic. For example, the gasdistribution plate 246 may be fabricated from quartz, silicon, siliconnitride, silicon carbide, alumina, aluminum nitride, etc. Additionally,the gas distribution plate 246 can be coated with a ceramic material,such as aluminum oxide or yttrium oxide. For example, the gasdistribution plate 246 may be coated with a material selected from thegroup consisting of Al₂O₃, Sc₂O₃, Sc₂F₃, YF₃, La₂O₃, Y₂O₃, and DyO₃.

Referring now to FIG. 4, a treatment system 300 is depicted according toanother embodiment. The treatment system 300 can, for example, besimilar to the embodiment of FIG. 2, wherein like reference numeralsdesignate same or similar components. Treatment system 300 comprises aradical delivery system 340 having a gas diffuser 344 coupled to anoutlet of the radical generation system 115. The gas diffuser 344distributes radicals received from the radical generation system 115within a process space 345 through a plurality of openings formed in agas distribution plate 346 coupled to the outlet of the gas diffuser344. For example, the gas diffuser 344 comprises a substantially conicalvolume. Additionally, for example, as shown in FIG. 4, the gas diffuser344 can comprise a first entrant region 342 coupled to a second entrantregion 343. The first entrant region 342 and the second entrant region343 may, for example, be substantially conical, wherein the half angleof the first entrant region 342 is less than the half angle of thesecond entrant region 343. For example, the half angle of the firstentrant region 342 may be less than or equal to approximately 45degrees. Alternatively, for example, the half angle of the first entrantregion 342 may be less than or equal to approximately 20 degrees.Alternatively yet, for example, the half angle of the first entrantregion 342 may be less than or equal to approximately 15 degrees. Thegas distribution plate 346 can, for example, be similar to theembodiment of FIG. 3.

Referring now to FIG. 5, a treatment system 400 is depicted according toanother embodiment. The treatment system 400 can, for example, besimilar to the embodiment of FIG. 2, wherein like reference numeralsdesignate same or similar components. Treatment system 400 comprises aradical delivery system 440 having a gas diffuser 444 coupled to anoutlet of the radical generation system 115. The gas diffuser 444distributes radicals received from the radical generation system 115within a process space 445. For example, the gas diffuser 444 comprisesa substantially conical volume. Additionally, for example, as shown inFIG. 5, the gas diffuser 444 can comprise a first entrant region 442coupled to a second entrant region 443. The first entrant region 442 andthe second entrant region 443 may, for example, be substantiallyconical, wherein the half angle of the first entrant region 442 is lessthan the half angle of the second entrant region 443. For example, thehalf angle of the first entrant region 442 may be less than or equal toapproximately 45 degrees. Alternatively, for example, the half angle ofthe first entrant region 442 may be less than or equal to approximately20 degrees. Alternatively yet, for example, the half angle of the firstentrant region 442 may be less than or equal to approximately 15degrees.

Referring now to FIGS. 6A and 6B, a treatment system 500 is depictedaccording to another embodiment. The treatment system 500 can, forexample, be similar to the embodiment of FIG. 2, wherein like referencenumerals designate same or similar components. Treatment system 500comprises a radical delivery system 540 having a gas diffuser 544coupled to an outlet of the radical generation system 115. The gasdiffuser 544 distributes radicals received from the radical generationsystem 115 within a process space 545. For example, the gas diffuser 544comprises a substantially conical volume. Additionally, for example, asshown in FIG. 6A, the gas diffuser 544 can comprise a first entrantregion 542 coupled to a second entrant region 543. The first entrantregion 542 and the second entrant region 543 may, for example, besubstantially conical, wherein the half angle of the first entrantregion 542 is less than the half angle of the second entrant region 543.For example, the half angle of the first entrant region 542 may be lessthan or equal to approximately 45 degrees. Alternatively, for example,the half angle of the first entrant region 542 may be less than or equalto approximately 20 degrees. Alternatively yet, for example, the halfangle of the first entrant region 542 may be less than or equal toapproximately 15 degrees.

As shown in FIGS. 6A and 6B, a diffuser plate 546 is located between anoutlet of the first entrant region 542 and the inlet of the secondentrant region 543 of gas diffuser 544. Alternatively, the diffuserplate 546 is located at an outlet of the second entrant region 543 ofgas diffuser 544. The diffuser plate 546 comprises a center body 548,such as a disc, supported by one or more support arms 547 (two supportarms are shown in FIG. 6B), leaving one or more passages 549 (twopassages are shown in FIG. 6B) through which radicals may flow. Thecenter body 548, which may be circular, rectangular, or of any shape, isconfigured to diffuse the axial momentum of the gas flow emanating fromthe output of the radical generation system 115. Optionally, asillustrated in FIG. 4, a gas distribution plate may also be useddownstream of the diffuser plate 546.

The diffuser plate 546 may be fabricated from a metal, such as aluminumor anodized aluminum, or a ceramic. For example, the diffuser plate 546may be fabricated from quartz, silicon, silicon nitride, siliconcarbide, alumina, aluminum nitride, etc. Additionally, the diffuserplate 546 can be coated with a ceramic material, such as aluminum oxideor yttrium oxide. For example, the diffuser plate 546 may be coated witha material selected from the group consisting of Al₂O₃, Sc₂O₃, Sc₂F₃,YF₃, La₂O₃, Y₂O₃, and DyO₃.

Referring now to FIG. 7, a treatment system 600 is depicted according toanother embodiment. The treatment system 600 can, for example, besimilar to the embodiment of FIG. 2, wherein like reference numeralsdesignate same or similar components. Treatment system 600 comprises aradical delivery system 640 having a gas diffuser 644 coupled to anoutlet of the radical generation system 115. The gas diffuser 644distributes radicals received from the radical generation system 115within a process space 645. For example, the gas diffuser 644 comprisesa substantially conical volume. Additionally, for example, as shown inFIG. 7, the gas diffuser 644 can comprise a first entrant region 642coupled to a second entrant region 643. The first entrant region 642 andthe second entrant region 643 may, for example, be substantiallyconical, wherein the half angle of the first entrant region 642 is lessthan the half angle of the second entrant region 643. For example, thehalf angle of the first entrant region 642 may be less than or equal toapproximately 45 degrees. Alternatively, for example, the half angle ofthe first entrant region 642 may be less than or equal to approximately20 degrees. Alternatively yet, for example, the half angle of the firstentrant region 642 may be less than or equal to approximately 15degrees.

As shown in FIG. 7, a diffuser plate 646 is located between an outlet ofthe first entrant region 642 and the inlet of the second entrant region643 of gas diffuser 644. Alternatively, the diffuser plate 646 islocated at an outlet of the second entrant region 643 of gas diffuser644. The diffuser plate 646 can, for example, be designed similar todiffuser plate 546 shown in FIGS. 6A and 6B; however, it may furthercomprise a conical center body 647 supported by two or more supportarms, leaving two or more passages through which radicals may flow. Theconical diffuser body 647, which may be circular, rectangular, or of anyshape, is configured to diffuse the axial momentum of the gas flowemanating from the output of the radical generation system 115.Optionally, as illustrated in FIG. 4, a gas distribution plate may alsobe used downstream of the diffuser plate 646.

Referring now to FIGS. 8A and 8B, a treatment system 700 is depictedaccording to another embodiment. The treatment system 700 can, forexample, be similar to the embodiment of FIG. 2, wherein like referencenumerals designate same or similar components. Treatment system 700comprises a radical delivery system 740 having a gas diffuser 744coupled to an outlet of the radical generation system 115. The gasdiffuser 744 distributes radicals received from the radical generationsystem 115 within a process space 745. For example, the gas diffuser 744comprises a substantially conical volume. Additionally, for example, asshown in FIG. 8A, the gas diffuser 744 can comprise a first entrantregion 742 coupled to a second entrant region 743. The first entrantregion 742 and the second entrant region 743 may, for example, besubstantially conical, wherein the half angle of the first entrantregion 742 is less than the half angle of the second entrant region 743.For example, the half angle of the first entrant region 742 may be lessthan or equal to approximately 45 degrees. Alternatively, for example,the half angle of the first entrant region 742 may be less than or equalto approximately 20 degrees. Alternatively yet, for example, the halfangle of the first entrant region 742 may be less than or equal toapproximately 15 degrees.

As shown in FIGS. 8A and 8B, a diffuser plate 746 is located at anoutlet of the second entrant region 743 of gas diffuser 744. Thediffuser plate 746 can, for example, be designed similar to diffuserplate 646 shown in FIG. 7. The diffuser plate 746 comprises a conicalcenter body 747 supported by one or more support arms, leaving one ormore passages through which radicals may flow. Alternatively, thediffuser plate 746 comprises a vapor distribution plate configured tosupport the conical center body 747, wherein a plurality of openings 749are formed through a peripheral region of the diffuser plate 746 betweenthe base of the conical center body 747 and the inner wall of the secondentrant region 743 of gas diffuser 744. The conical center body 747,which may be circular, rectangular, or of any shape, is configured todiffuse the axial momentum of the gas flow emanating from the output ofthe radical generation system 115.

Referring still to FIGS. 8A and 8B, treatment system 700 may furthercomprise a pedestal edge ring 750, and/or a diffuser plate edge ring752, or both, in order to impede the flow of process gases beyond aperipheral edge of substrate 125 to vacuum pumping system 170. Thepedestal edge ring 750, or the diffuser plate edge ring 752, or both,may be configured to reduce the flow-through space at the peripheraledge of substrate 125 by anywhere from approximately 10% toapproximately 80%, and desirably from approximately 20% to approximately50%. This can provide more uniform distribution of the radicals acrossthe substrate and/or can improve the treatment rate of the substrate.

The pedestal edge ring 750, or the diffuser plate edge ring 752, orboth, may be fabricated from a metal, such as aluminum or anodizedaluminum, or a ceramic. For example, each ring may be fabricated fromquartz, silicon, silicon nitride, silicon carbide, alumina, aluminumnitride, etc. Additionally, each ring can be coated with a ceramicmaterial, such as aluminum oxide or yttrium oxide. For example, eachring may be coated with a material selected from the group consisting ofAl₂O₃, Sc₂O₃, Sc₂F₃, YF₃, La₂O₃, Y₂O₃, and DyO₃.

FIG. 12 presents a flow chart of a method for removing residue from asubstrate according to an embodiment. The flow chart 1000 begins in 1010with disposing the substrate with the residue on a pedestal in a processchamber. The pedestal may be any of the pedestal configurations of FIGS.9-11 and process chamber can include any one of the process chambersdescribed in FIGS. 2 through 8, or any combination thereof. The residuemay include residue from an etching process.

In 1020, a process gas is introduced to a radical generation chambercoupled to the process chamber. In one embodiment, the process gascomprises N_(x)O_(y), wherein x and y are integers greater than or equalto unity. The process gas can include one or more of NO, N₂O, or NO₂, ora combination of two or more thereof. Preferably, the process gascomprises N₂O, which is expected to provide a good treatment rate whenusing a remote radical generation system such as those disclosed herein.The N_(x)O_(y) gas may be used with or without N₂ and/or O₂ gases asdiscussed below. Alternatively, the process gas further comprises anoxygen containing gas, such as O₂, CO, or CO₂, or a combination of twoor more thereof. The present inventors have recognized that while anoxygen containing gas may be undesirable for a local plasma due topossible damage to the substrate (particularly in FEOL operations), anoxygen containing gas used in a remote radical generator can facilitatetreatment rate of the substrate while minimizing damage. Alternatively,the process gas further comprises a nitrogen containing gas, such as N₂,NH₃, or NF₃, or a combination of two or more thereof. Alternatively, theprocess gas further comprises a halogen containing gas, such asC_(x)F_(y), wherein x and y are integers greater than or equal to unity.Alternatively yet, the process gas further comprises N₂ and O₂.Alternatively yet, the process gas consists of N₂O, N₂ and O₂.Alternatively, the process gas further comprises an inert gas, such as anoble gas.

For example, a process parameter space can comprise a chamber pressureof about 1 to about 10 Torr, a process gas flow rate ranging from about3 to about 5 slm, and a pedestal temperature ranging from about 100degrees C. to about 300 degrees C.

In 1030, radicals of the process gas are formed in the radicalgeneration chamber. The radicals may be formed by forming plasma andinducing dissociation of the process gas. Alternatively, othertechniques for dissociating the process gas may be employed, includingelectromagnetic (EM) radiation such as ultraviolet (UV) radiation.

In 1040, the radicals formed from the process gas are transported fromthe radical generation chamber to the process chamber. For example, theradical may be transported through any one of the radical deliverysystems depicted in FIGS. 2 through 8, or any combination thereof.

In 1050, the substrate is exposed to the flow of radicals, and theresidue is removed. The substrate may be exposed to radicals while notbeing exposed to plasma in the radical generation chamber.

Although only certain embodiments of this invention have been describedin detail above, those skilled in the art will readily appreciate thatmany modifications are possible in the embodiments without materiallydeparting from the novel teachings and advantages of this invention.Accordingly, all such modifications are intended to be included withinthe scope of this invention.

1. A treatment system, comprising: a process chamber, including aprocess space; a remote radical generation system coupled to saidprocess chamber and configured to receive process gas and produceradicals from said process gas and transport said radicals to saidprocess space in said process chamber above a substrate; a pedestalcoupled to said process chamber and configured to support said substratein the process space of said process chamber and control the temperatureof said substrate, wherein said pedestal comprises one or more groovesformed in an upper surface of said pedestal, at least one of said one ormore grooves extends to an outermost peripheral edge of said pedestal,and said pedestal does not have a back side gas flow mechanism coupledto said one or more grooves; and a vacuum pumping system coupled to saidprocess chamber and configured to evacuate said process chamber.
 2. Thetreatment system as recited in claim 1, further comprising: a gasdistribution system coupled to an outlet of said radical generationsystem and configured to distribute said radicals above said substrate.3. The treatment system of claim 1, wherein said pedestal comprises oneor more heating elements, or one or more cooling elements, or acombination thereof, configured to control said temperature of saidsubstrate.
 4. The treatment system of claim 1, wherein said pedestal isformed of aluminum having a coating thereon.
 5. The treatment system ofclaim 4, wherein said coating is an anodic layer.
 6. The treatmentsystem of claim 4, wherein said coating contains at least one column IIIelement.
 7. The treatment system of claim 4, wherein said coatingcontains at least one element selected from the group consisting ofAl₂O₃, Sc₂O₃, Sc₂F₃, YF₃, La₂O₃, Y₂O₃, and DyO₃.
 8. The treatment systemof claim 1, wherein said pedestal comprises a heating control elementhaving one or more resistive heating elements.
 9. The treatment systemof claim 1, wherein said pedestal comprises a heating control elementhaving one or more thermo-electric devices.
 10. The treatment system ofclaim 1, wherein said process chamber is formed of aluminum having acoating thereon.
 11. The treatment system of claim 10, wherein saidcoating is an anodic layer.
 12. The treatment system of claim 10,wherein said coating contains at least one column III element.
 13. Thetreatment system of claim 10, wherein said coating contains at least oneelement selected from the group consisting of Al₂O₃, Sc₂O₃, Sc₂F₃, YF₃,La₂O₃, Y₂O₃, and DyO₃.
 14. The treatment system of claim 2, wherein saidgas distribution system comprises: a gas distribution plate fordistributing said radicals in said processing chamber through aplurality of openings; and a plenum coupled to said outlet of saidradical generation system, and configured to receive said radicals fromsaid radical generation system and supply said radicals to saidplurality of openings in said gas distribution plate.
 15. The treatmentsystem of claim 14, wherein said gas distribution plate is formed ofaluminum having a coating thereon.
 16. The treatment system of claim 15,wherein said coating is an anodic layer.
 17. The treatment system ofclaim 15, wherein said coating contains at least one column III element.18. The treatment system of claim 15, wherein said coating contains atleast one element selected from the group consisting of Al₂O₃, Sc₂O₃,Sc₂F₃, YF₃, La₂O₃, Y₂O₃, and DyO₃.
 19. The treatment system of claim 1,further comprising: a process gas supply system coupled to said radicalgeneration system, and configured to supply said process gas to saidradical generation system.
 20. The treatment system of claim 19, whereinsaid process gas supply system is configured to supply one or more ofO₂, N₂, NO, NO₂, N₂O, CO, CO₂, NH₃, NF₃, or CF₄, or any combination oftwo or more thereof.
 21. The treatment system of claim 20, furthercomprising: an edge ring coupled to said process chamber and configuredto surround said process space in order to impede the flow of radicalsbeyond a peripheral edge of said substrate.
 22. The treatment system ofclaim 21, wherein said edge ring comprises a pedestal edge ring coupledto a peripheral edge of said pedestal.
 23. The treatment system of claim2, further comprising: an edge ring coupled to said process chamber andconfigured to surround said process space in order to impede the flow ofradicals beyond a peripheral edge of said substrate, wherein said edgering comprises an edge ring coupled to a peripheral edge of said gasdistribution system.
 24. The treatment system as claimed in claim 1,wherein said one or more grooves comprise: a first array of groovesextending in a first direction; and a second array of grooves extendingin a second direction substantially perpendicular to the firstdirection.
 25. A treatment system comprising: a process chamber,including a process space; a remote radical generation system coupled tosaid process chamber and configured to receive process gas and produceradicals from said process gas and transport said radicals to saidprocess chamber above a substrate; means positioned in said processchamber, for supporting the substrate with minimal slippage of thesubstrate, wherein said means for supporting the substrate comprises oneor more grooves formed in an upper surface of said means for supportingthe substrate, at least one of said one or more grooves extends to anoutermost peripheral edge of said means for supporting the substrate,and said means for supporting the substrate does not have a back sidegas flow mechanism coupled to said one or more grooves; means forheating the substrate; and a vacuum pumping system coupled to saidprocess chamber and configured to evacuate said process chamber.
 26. Thetreatment system as recited in claim 1, further comprising: wherein saidpedestal comprises one or more grooves formed in an upper surface ofsaid pedestal and said grooves are in contact with the substrate, andwherein said grooves are open to the edge of the substrate.
 27. Thetreatment system as recited in claim 1, wherein said one or more groovesextends beyond a portion of the upper surface of said pedestal that isconfigured to contact said substrate.
 28. The treatment system asrecited in claim 25, wherein said one or more grooves extends beyond aportion of the upper surface of said means for supporting the substratethat is configured to contact said substrate.